Effectively Prefetching Remote Memory with Leap


Hasan Al Maruf and Mosharaf Chowdhury, University of Michigan
Awarded Best Paper!


Memory disaggregation over RDMA can improve the performance of memory-constrained applications by replacing disk swapping with remote memory accesses. However, state-of-the-art memory disaggregation solutions still use data path components designed for slow disks. As a result, applications experience remote memory access latency significantly higher than that of the underlying low-latency network, which itself can be too high for many applications.

In this paper, we propose Leap, a prefetching solution for remote memory accesses due to memory disaggregation. At its core, Leap employs an online, majority-based prefetching algorithm, which increases the page cache hit rate. We complement it with a lightweight and efficient data path in the kernel that isolates each application’s data path to the disaggregated memory and mitigates latency bottlenecks arising from legacy throughput-optimizing operations. Integration of Leap in the Linux kernel improves the median and tail remote page access latencies of memory-bound applications by up to 104.04× and 22.62×, respectively, over the default data path. This leads to up to 10.16× performance improvements for applications using disaggregated memory in comparison to the state-of-the-art solutions.

Open Access Media

USENIX is committed to Open Access to the research presented at our events. Papers and proceedings are freely available to everyone once the event begins. Any video, audio, and/or slides that are posted after the event are also free and open to everyone. Support USENIX and our commitment to Open Access.

@inproceedings {254352,
author = {Hasan Al Maruf and Mosharaf Chowdhury},
title = {Effectively Prefetching Remote Memory with Leap},
booktitle = {2020 USENIX Annual Technical Conference (USENIX ATC 20)},
year = {2020},
isbn = {978-1-939133-14-4},
pages = {843--857},
url = {https://www.usenix.org/conference/atc20/presentation/al-maruf},
publisher = {USENIX Association},
month = jul

Presentation Video